Pathogenicity of Five Fungal Species Isolated From Eldana Saccharina (Walker) (Lepidoptera: Pyralidae)

Abstract

Maize is one of the most important cereal crops grown in Africa by commercial and small-scale farmers. It serves as a staple food for millions of people in Africa. Maize production is, however, constrained by many biotic factors including lepidopteran stem borers such as Eldana sac-charina, which feed inside stem and rob the maize plant of water and nutrients. Many of the currently existing methods of controlling stem borers are either too expensive or inefficient. There is therefore, a need to find alternative control methods including the use of biological agents such as fungal pathogens. Dead Eldana saccharina larvae were collected from harvested maize farms around Kumasi in the Ashanti Region of Ghana. They were taken through a proc-ess to isolate and identify fungal pathogens with which pathogenicity tests were performed on healthy E. saccharina larvae. The median lethal time (LT50) was determined for the fungal spe-cies that were pathogenic to E. saccharina. The isolated fungal species were Aspergillus flavus, Verticillium albo-atrum, Trichothecium spp., Fusariunm oxysporum and Alternaria brassici-cola. Out of the five, A. flavus had the largest corrected percentage mortality of 66.3 % at a con-centration of 1x107c.fu./ml. A. flavus, and V. albo-atrum., were pathogenic to E. saccharina. Trichothecium spp. was moderately pathogenic while F. oxysporum and A. brassicicola were not pathogenic to E. saccharina. A. flavus and V. albo-atrum could, therefore, be incorporated into an integrated approach to control E. saccharina.